In contemplating any life and death moral dilemma, one is often struck by the possible importance of two distinctions; the distinction between killing and “letting die”, and the distinction between an intentional killing and an action aimed at some other outcome that causes death as a foreseen but unintended “side-effect”. Many feel intuitively that these distinctions are morally significant, but attempts to explain why this might be so have been unconvincing. In this paper, I explore the problem from an explicitly consequentialist point of view. I first review and endorse the arguments that the distinctions cannot be drawn with perfect clarity, and that they do not have the kind of fundamental significance required to defend an absolute prohibition on killing. I go on to argue that the distinctions are nonetheless important. A complete consequentialist account of morality must include a consideration of our need and ability to construct and follow rules; our instincts about these rules; and the consequences (to the agent and to others) that might follow if the agent breaks a good general rule, particularly if this involves acting contrary to moral instinct. With this perspective, I suggest that the distinctions between killing and letting die and between intending and foreseeing do have moral relevance, especially for those involved in the care of the sick and dying.